Compressor



COMPRESSOR 1922 2 Sheets-Sheet l Filed Atari-1 14 Sl Nl fr s,

2 Sheets-Sheet 2 COMPRESSOR A. D. SHAW ET AL Filed April 14,

Sept. 16 1924.

WITNESS ARTHUR D. SHAW AND JOSEPBS It. THOMAS, OF PHILADELPHIA, PENNSYLVANIA,

ASSIGNORS, BY MESNE ASSIGNMENTS, T0 WIDMER COMPRESSOR, ING., OF PA-V DELPHIA, PENNSYLVANIA, A CORPORATION F DELAWARE.

COMPRESSOR.

Application led April 14, 1922. Serial No. 552,511.

To all whom t may concern;

Be it known that we, ARTHUR D. SHAW and JOSEPH R. THOMAS, citizens of the United States, and residents of the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Compressors, of which the following is a specification, reference being had to the accom anying drawings.

Our invention re ates more particularly to electrically driven compressors adapted for effecting compression of the refrigerant in refri erating units intended for household an other similar uses as distinguished from large refrigerating installations e1nployed in commercial refrigeration or in the manufacture of artificial ice, a principal object of the invention being to provide an entirel self-contained compressor which is "'capa le of being driven at high speeds and in which the moving parts are suitably disposed and balanced in such manner as to avoid excessive vibration when so driven.A

A further object of our invention is to provide a compressor adapted for the aforesaid purposes which is entirely devoid of, 'stuiiing boxes, glands, or other devices for preventing leakage of the refrigerant gas from the interior of the compressor adjacent shafts or other moving parts extending through the casing or other portion of the machine, as it vhas been found in practice .that compressors embodying such devices require constant care, expense and attention in an effort to make them perform their intended function of preventing leakage of the refrigerant; a condition which is vextremelyundesirable in the class of refrigerating installations in which these small compressors are employed. As all of the movlng parts are entirely self-contained within the casing of our improved compressor, however, no devices for preventing refrigerant leakage adjacent any moving part are necessary and none are employed.

A still further object of the invention is to provide a compressor in which all of the rotating parts are supported on ballbearings and of such design and construction that adequate and thorough lubrication of all the movin during operatlon, a condition which is exparts Tis constantly effectedl tremely important in prolonging the life of the machine.

A s till` further object of the invention is to utilize-1n the construction of the compresser a suitable electric motor of standard design as a source of motive power and to arrange substantially similar compressing mechanism at opposite ends of the field ring 00 thereof in place of the ordinary vbells customarily utilized at the ends of thefield r1ng,\ and to. provide means for effecting adequate cooling of the motor armature and windings; in thdpreferred form of the inf 05 ventlon by intr pressure refrigerant ucin the expanded low irectly into the interior of themotor from'whence it is drawn over and through the coils to the compressing mechanisms disposed laterally of the 7 ring at each end thereof in 'which it is com-A cpressed, and from thence discharged to the esired part of the refrigerating system, and

in a modified construction by .utilizing a 'Y ing description taken in connection 'with lthe 80 drawin s forminga art hereof. j

In e elcting the o jects of our invention 'We preferably utilize a suitable electric motor of direct or alternating current or induction type, such motors normally comprising' a central field lring having a bell removably attached to each end thereof which serves to support the armature shaft in. suitable bearings as well as the cages in which the brushes are disposed if the same are emplo ed, the armature being, of course, positionedywithin the ring. When employing a motor of this general character we remove the bells from the ends of the field ring and substitute for each bell a suitable crank case which is effective to4 support a cylinder in which the compression is effected by a reciprocating piston and to house the mechanism through which the piston is actuated from the rotatable armature shaft,

as well J as to provide asupport for the bearings on 'which thel latter rotates and for the brush cages if employed. Y

. In the accompanying .drawings we have illustrated in Figs. 1 and 2 a preferred ernbodiment of our invention, Fig. 1 being a view partially in central vertical section and partially in side elevation and Fig. 2 being an end elevation on a slightly reduced scale. In Fig. 3l we have illustrated a slightly modified form of the invention, the said figure being a fragmentary view partially in central vertical section and partiall in side elevation of the motor and one o .the compressing .mechanisms Like numerals are utilized to indicate the same partsin the different figures, and as the mechanism at both ends of the field ring is the same in all substantial respects, we have designated the parts at the left hand end of the machine, viewed as in Fig. 1, by the same numerals as those at the right hand end but with the addition of a prime thereby avoiding needless repetition in the following description which will .thus be understood as equally applicable to the mechanism at each end of the motor.

Referring more particularly to the form. of the invention shown in Figs. 1 and 2, the same comprises a motor of any suitable construction and having a field ring 1. As the motor employed is of standard type no attempt has been made in the drawings to illustrate any of the parts thereof save the lield ring and portions of the armature shaft 2, but it will of course be understood that the armature and field windings are disposed in the customary manner within the ring and that provision is made for at'- tachment of the wires -through which the current is led in. Removably secured to the ends ofthe field ring, as by the screws 3, are cylindrical housings 5, 5 which may be provided with flanges 6, 6 for the reception of the screws and which abut the end facesof the ring. These .housings in effect replace the ordinary bells employed in motors of this type and are operative, among other things, to sup rt the vcrank cases 7, 7 which are prefera ly formed integrally with their respective housings. Each crank case is substantially cylindrical in form and divided from its adjacent housing by a partition 9 provideld with a preferably integral,. inwardly directed annular cup 10, the interior of which is machined to receive an annular ball bearing, generally designated as 12 and preferably of a well known self-aligning type, this bearing serving to rotatably support one end of the armature shaft 2 Which extends entirely through the bearing, through a suitable opening in the partition and into the chambei" 14 formed within the crank case. Preferably the extreme outer end of the crank case is initially left open and adapted to be operatively closed by a cover 15 held in position by screws 16, so that by removing the cover convenient acc/es may be had Lmt to the interiorof the case. The case is also provided with a suitable integral base 18 having bolt holes 19 for the reception of bolts by means of which the machine may be attached to a supporting surface.

Formed integrally with the crank case .and extending radially upward and outward therefrom is a cylinder block 2() preferably provided with a plurality of horizontally disposed outwardly directed radiating danges 21. 'lhis block is preferably cored out between its upwr and lower extremities thereby providing an annular chamber 23 within which is rigidly dis osed a sleeve 25 having an overhanging ange 26 at its upper end which rests in a chamfer in the end of the block, the sleeve being laterally supported by inwardly directed annular Hanges 27 at the extremities of the cored out space, the interior of the sleeve thus forming the compression cylinder in which a piston 30 of any suitable type and arranged to form a good sliding fit in the sleeve is disposed for reciprocation. llf desiretd, the piston may be provided with one or more piston rings (not shown) for preventing leakage between` the piston and the sleeve in the well known manner, while a wrist pin 32 is arranged to extend transversely of the piston to receive the upper end of the connecting rod 35 in the usual manner, the pin being either secured to the rod and arranged to oscillate in the piston or secured to the piston to provide a surface on which the rod may oscillate.

'llhe opposite or lower end of the connecting rod is arranged to be driven from the armature shaft through the medium of a. suitable crank pin and while the connection between these parts may be made in any suitable or convenient manner we prefer and as shown, to dispose a relatively thick washer 37, having its outer surface inwardly beveled, on the outer squared end of the varmature shaft so that the inner end of the washer abuts a shoulder 38 formed on the shaft in the plane of the outer face of bearing 12. Formed integrally with this washer and projecting outwardly from its outer face is a crank pin 39, the distance between the axis of this pin and the shaft being equal to one-half of the. desired stroke of the piston, and the pin being arranged toy extend through an eccentrically positioned hole formed in a fly wheel 40 conveniently in the form. of a solid disk supported on the extremeouter end of the armature shaft. Disposed on the crank pin in abutting relation with the outer face of the ily wheel is a washer 42 which liinits the inward movement of an annular ball bearing, generally designated as da, disposed in the lower or large end of the connecting rod 35 and against the outer face of which a dat washer t5 is drawn up by a nut 46 positioned on the extreme outer end of the crank pin; the nut which may be castellated being preferably locked in position by a cotter pin 47, and that portion of the pin on which the nut and washer are located being reduced in diameter so as to form a shoulder in the plane of the outer bearing 44.

' For effecting the admission and exhaust of the gas' into and from the cylinder, suitable inlet and exhaust valves are provided and arranged to alternately open and close 1n correspondence with the movements of the piston. .Convenientl the inlet valve may comprise a ball disposed in a` chamber 51 formed in the upper end of the cylinder block and cooperative with a downwardly inclined conical seat at the lower end of the chamber to control a port 52 extending into the cored space or chamber 23, which latter is connected by a plurality of ports 53 with the crank chamber 14. A transversely lextending port 55 leads from the upper end of the chamber 51 to the interior ofthe cylinder sleeve, and a light spring 57 is preferabl interposed in the chamber between the ba l and the under side of the cylinder head 60 which extends over the upper end of the block to close the cylinder and is retained in position by bolts 61. Preferably the upper face of the center of the head is provided with a plurality of radiating flanges 62 and a asket 63 is ordinarily disposed between t e other end of the cylinder head block and the cylinder head to form a tight joint at this point.

The exhaust valve for the cylinder may be substantially similar to the inlet valve and preferably comprises a ball 65 disposed in 'a chamber 66v formed in the cylinder block diametrically opposite the chamber 5l and into the upper end of which is threaded a bushing 67 having its lower facebeveled to form a seat for the ball and through which a port `68 communicates with a horizontally disposed port 69 in the upper end of the cylinder block and extending into the cylinder. .From the lower end of the chamber a port 70,1eads through a boss 71 formed on the block and into which is threaded one end of a ipe P which unites with a similar ipe extending from the boss 71', a sing e pipe P .leadin from these pipes to the high pressure si e of the refrigeratin system.

t will be observed that the crank pins 39, 39 are diametrically disposed with respect to the axis of the armature shaft so that when one piston is at the end of its down or suction stroke the other piston is at the end of its up or compression stroke and as the moving parts on opposite ends of the machinefare preferably made similar in all respects a gel-y smooth running and Well balanced machine results.

found that owing to the construction of the motor it is undesirable to permit the introduction of oil thereto, the ports 75 may be omitted or a pipe extending from one crank case to the other and by-passing the motor may be employed instead. Furthermore, it will be understood that in case it is requisite to utilize cages'or other devices for supporting the motor brushes, the same may be readily mounted on the exterior of the cups 10 which for this purpose may be extended inwardly sufliciently far to` afford the req-I uisite support, as will be readily apparent to those familiar with [the art. v

In the preferred embodiment of the invention, in order to effect the coolingfof the motor windings and other parts, we connect the inlet pipe I through which the gas which is to be compressed 1s brou ht to the machine directly with the interior of the field ring by drilling and tapping the latter and screwing the plpe thereinto so that the gas is free to iow into the space within the field ring in which the armature is positioned. For permitting the passage of the gas from this point to the crank cases, the partitions 9 may be providedwith a plurality of suitably disposed ports 78 so thatras-a suction is created Iin either cylinder du ing the down stroke of the piston therein, the gas which fills the armature space, crank cases and chambers 23 surrounding the cylinder sleeves is drawn past the inlet valve and into that cylinder, in which, on the ensuing upstroke of the piston, it is compressed and forced out past the exhaust valve to the pipe P. It will be apparent that the drawing of the gas through the ports 78 creates a substantially constant flow or current of the gas toward each end of the armature and lover the windings thereof thus serving to-keep the latter, as well as the lield coils, in suitably cooled condition.

In the form of the invention shown in Fig.

3 the cooling of these parts is accomplishedin a slightly different manner, namely, by providing the fieldl ring with a suitable surrounding water jacket 80 into which cooling Y water is introduced through a pipe 81 and from which it is discharged through a pipe 82. Preferably under these conditionsftne 'acket is constructed, as clearly shown in ig. 3, so that a somewhat greater body or depth of water will be maintained near the upper part of the field ring than near the lower part thereof so as to compensate for the greater heat adjacent the former point. Additionally, under these circumstances the ports 52 through which the gas passes to the inlet valves are each arranged to communicate with an inlet pipe ll which is threaded into a boss S4 formed on the cylinder block adjacent the inlet valve and through which the gas to be compressed is conducted to the machine. Preferably, however, the port 52 is also arranged to communicate with the chamber 23 and adjacent crank case in the manner already described in order that a balanced pressuremay at all times ybe maintained in the interior of the machine.

It will thus be observed that we have provided a compressor in which all of the moving parts are entirely enclosed and thoroughly lubricated, which is simple in construction and design and capable of being driven at high Speeds Without injury to the parts or excessive vibration and which is capable of use over long periods of time without any attention or adjustment Whatsover.

lt will also be apparent that connected as shown in the piping of a circulating system such as is commonly employed in effecting refrigeration, the compressor may broadly be considered as comprising a closed casing forming an integral part of the means through which the circulation o-f the refrigerant fluid is effected and operative to enclose the moving parts through the medium of which the expanded fluid is drawn from the low pressure side of the system into one part cf the casing and discharged in compressed condition from another part thereof into the high pressure side. So far as we are aware, irrespective of the particular type or kind of compressing or circulating means employed, we believe it to be broadly new to utilize the casing of the compressor as an integral part of the means in which the fluid is circulated and to entirely dispose the moving parts of the compressing mechanism therein, the results effected by such an arrangement being of-great utility in that the necessity of employing glands, stufiing boxes or the like, with their attendant disadvantages, in an effort to prevent fluid leakage adjacent drive shafts or other moving parts extending outside or through the walls of the means in which the circulation of the fluid carried on is entirely avoided, and We therefore claim this feature in its broadest as ect.

oreover, While we have more especially referred to the use of the invention in the compression of refrigerant gas in small refrigerating systems, it will be understood that the same may be employed with equal facility as a pump, or for other purposes,

and that while we have illustrated and Cleneoaeoe scribed with considerable particnlarity certain embodiments thereof for the purpose of enabling those skilled in the ait to comprehend and practice the invention, we do not thereby desire or intend to in an manner limit ourselves to any precise details of construction and arrangement of the several elements, as our invention includes such modifications in the form, construction and arrangement thereof and the utilization of such equivalent means therefor as are comprehended by and fall within the scope of the appended claims.

Having thus described our invention, we claim and desire to protect by Letters Patent of the United States 1. ln a compressor, the combination with a motor having a field ring, of a closed crank case supported at each side of the ring, a partition provided with ports between each crank case and the ring, a cylinder supported on each crank case andhaving inlet and exhaust valves, a piston in each cylinder, means for actuating the piston from the motor, and an inlet connection communicating with the interior of the motor whereby the gases to be compressed in the cylinders are first directed into the motor and thence led through said ports and the respective inlet valves of the c linders.

2. ln a compressor, the combination with a motor having a field ring, of an inlet connection to the interior of the ring, a closed crank case supported at each end of the ring and communicating with the interior thereof, a cylinder supported on each cranlr case, a piston adapted to reciprocate in the cylinder, means for actuating the piston from the motor, and an inlet valve disposed to control communication between the interior of each crank case and the interior of each cylinder whereby on the suction stroke of each piston a char e of the gas to be compressed will be drawn from said inlet through said motor and crank case and into said cylinder.

3. A. compressor comprising a centrally disposed motor having a field ring andan inlet connection thereto through which the gas to be compressed may pass to the interior of the motor, a closed crank case disposed at each end of the motor, ports connecting the interior of the motor withthe interior of the crank case, compressing means adjacent each case including a cylinder and a piston actuated from the motor, a passage between each crank case and its adjacent cylinder, and an inlet valve disposed to control said passage, whereby when a suction is formed in each cylinder the gas to be compressed. is drawn through said motor and the adjacent crankl case into said cylinder.

4. lln a compressor, the combination with a motor, of a closed crank case disposed at each end of the motor, a partition separating the inte-rior of each crank case from the interior of the ring, a ball bearing for the armature shaft o'f the motor supported from each partition, a cylinder supported on each crank case, an inlet valve controlling the admission of gas to each cylinder, and means comprising a plurality of ports for insuring a balanced pressure 1n said motor and said crank case and iu said cylinder when said inlet' valve is open.

5. In a compressor, the combination of a centrally disposed motor having an inlet through which the gas to be compressed is admitted to its interior, a closed crank casef disposed at each end of the motor, a cylinder supported on each crank case, a reciprocatlng piston in each cylinder actuated from the motor, and means including a pluralit of ports and an inlet valve adjacent eac cylinder whereby on the suction stroke of thepiston the gas will be drawn from said inlet through said\motor, the adjacent crank case and past said inlet valve into said cylinder, and an exhaust valve controlling a part leading' from each cylinder and adapted to open on the compression stroke of the piston therein. I y

In witness whereof, We have hereunto set our hands this `13th da of April, 1922.

ART UR D. SHAW. JOSEPH R. THOMAS. 

